Printing plate cylinder



March 3l, 1936. A W WOOD PRINTING PLATE CYLINDER NNI kw Filed Feb. 8,1935 mi, x.

Patented Mar. 3l, 1936 UNITED `sra'llzs PRINTING PLATE CYLINDER Henry A.Wise Wood, New York, N. Y., assignor4 I to Wood Newspaper MachineryCorporation,

New York, N. Y., a corporation of Virginia Application February 8, 1933,Serial No. 655,683 solaim's. (ci. 1011-378) The principal objects ofthis invention are to provide a printing plate cylinder with meansthereon for clamping the printing plates inside their surfaces so thatthe clamping means engaging the beveled and straight edges of the platesare not depended upon entirely for. holding the plates, and to provide aconstruction of the cylinder which will enablethe printing plates to bemade without necessitating any edge matelo rial solely for clampingpurposes, thereby permitting the employment of very narrow margins andan addition to the printed matter on each page.

Other objects and advantages of the invention Will appear hereinafter.

Reference is to be had to the accompanying drawing, in which Fig. 1 is aradial sectional view of a part of a printing plate cylinder showingthree plates thereon clamped in accordance with this invention;

Fig. 2 is a similar view showing the end plate unclamped;

Fig. 3 is a similar view showing the position of the end plate whenready to be removed from the cylinder; v

Fig. 4 is a modication like Fig. 1 showing the entire elimination ofsurfaces on the plates for use in clamping the plates on the cylinder,thus enabling the plates to be made with the narrowest possible margins.

In printing plants using stereotype plates it has been customary tosecure the plates on the plate cylinders by beveled clamps operatingagainst beveled curved edges of the plates. In some cases the straightedges of the plates also are beveled and clamped down on the cylinder.The trend in newspaper plants has been toward higher speeds and the edgeclamping means have not always proved suilicient to hold the platesunder the increased centrifugal force produced.

In the newspaper printing business there has been an ever increasingdemand for narrower margins on newspapers. With the customary bevelededges for engagement with end clamps, center clips, and center rings,there is an irreducible limit in margins below which it is impossible togo. One object of this invention is to reduce and in fact, in somecases, eliminate the beveled edges and thus that part of the plate atthe edges which is employed for clamping purposes only. Thus the platescan be made with the narrowest possible margins and there will have tobe no additional metal employed for clamping purposes. AIn other words,the entire surface of the plate can be used forprinting matter andplates of the same size as are now used and will furnish more Yroom forprinting surfaces. y

In the form shown in'. Figures 1, 2 and l3 the printing cylinder I0 isprovided on opposite sides of the middle of the cylinder with sets of`integral projections II inclined in one direction and inclined inopposite directions on opposite sides lo' of the center. Theseprojections are all inclined at the Vsame vangle and at the same angleon both sides of each projection.

In thisforma center clip I2 is used and a center ring I3, the centerring being the same I5' as usual and the center clip having projectionson its opposite sides operating in ways I4 and being free to move backand forth to accommodate the plates. Also an end clamp I5 is used havinga usual operating means I6. -Of course, 20 the end clamp, center clamp,and center ring are provided with beveled edges I1, I8 and I9 forengaging the beveled edges of the printing plates P and holding them inposition;

The center ring being stationary and the cen- 25 ter clip movable, theinside plate can be clamped Aagainst the center ring and the outsideplate between the center clip and the end clamp by motion of the endclamp alone. These beveled surfaces are employed here as usual for casesin 30 which it is not desired to change the shape of the plates. In allcases, however, the projections II engage in recesses or indentations 20on the inner or concave sides of the plates. These recesses have bevelededges beveled on the same 35 angle as the projections I I and beveledthe same way at the inner and outer end. The recesses are at least longenough to receive a projection plus the length required by the bevel atits end. Thus they can receive these projections as shown 40 in Fig. 3.The plates can be moved along to the position shown in Fig. 1 by the endclamp and the plates will be held rmly.` These bevel surfaces hold theplates on the ,cylinder at points between the edges of the plates andassist in 45 preventing the plates being dislodged or loosened by thehigh degree of centrifugal force to which they are subjected in modernnewspaper practice. The clamping along the straight edges oi' the platescanbe eliminated in Vsome cases. 50

In the form shownvin Fig. 4 a construction is shown in which theclamping-by the center clip and center ring can be entirely avoided andthe surfaces of the plate employed for clamping the plate in positionare entirely eliminated from the 55 all four plates have square ends andthey all abut against each other. These plates are held by theprojections Il above described in the recesses 20 and not by the centerclips and center ring heretofore employed. This not only eliminates thebevel undercut on the end clamp but entirely' eliminates the centerclips and center rings. It will be seen that in this form of theinvention the margins can be reduced to an absolute minimum and theamount of printing on the page will reach the maximum.

In this first formi it will be obvious that the .projections il on oneside of the center ring I3 slant in one direction, whereas thecorresponding lprojections l I- on the other side of the center ringslant in the opposite direction, but in the form shown in Fig. 4 theycanall slant in the same direction, as there is no stationary center ringor any substitute for it employed, the plates being clamped simplybetween the end clamps. It will be obvious that the plates are easilyremoved simply by moving the end clamp out as shown in Fig. 2 and thenmoving each plate a little ways in the same direction as shown in Fig.3.

Although I have illustrated and described only two forms of theinvention I am aware of the fact that other modifications` can be madetherein by any person skilled in the art without departing from thescope of` the invention as expressed in the claims. Therefore, I do notwish to be limited in this respect otherwise than as set forth in theclaims, but what I do claim iszl. As an article of manufacture, aprinting plate cylinder having integral inclined projections on itssurface slanting away from the middle of the cylinder for holding theprinting plates thereon at points within their surfaces, saidprojections on one side of the longitudinal middle of the cylinder allslanting in the same direction longitudinally.

2. As an article of manufacture, a printing plate cylinder havingintegral projections on its surface for engaging in correspondingrecesses in the printing plates and end clamps engaging the curved endsof the printing plates constituting the sole means separate from theprinting cylinder for clamping a series of plates in position.

3. The combination with a printing plate cylinder having integralinclined projections on its cylindrical surface, of a fixed center ringhaving inwardly beveled undercut surfaces for receiving the edges of theinside plates; a longitudinally movable center clip having rearwardlybeveled undercut recesses for receiving the beveled edges of an outerand inner plate, and an end clamp having an inwardly beveled edgeslanted in a direction opposite to that of the recesses of the centerclip for receiving the outer edge of the outer plate, positively holdingthe plate between it and said projections, and constituting a movablemeans for clamping an inner and outer plate on the cylinder.

4. The combination of a printing plate cylinder having slantinglongitudinal projections extending outwardly from the surface thereof,and

a movable end clamp having a surface in a plane f perpendicular to theaxis of the cylinder for engaging the end of a printing plate and movingthe plate along the cylinder so that said slanting projections will holdthe plate by engagement with the slanting surfaces of their recesses.

5. The combination with a printing plate cylinder having a series ofprojections on its surface, all slanting in the same direction, a seriesof vcurved printing plates thereon, each having recesses in its concavesurface for receiving said projections and having square edges, saidsquare edgesabutting against each other, and an end clamp having asquare surface abutting against the square edge of the outer platel forforcing said plates along the cylinder to cause them to be clamped bysaid projections.

HENRY A. WISE WOOD.

